The very text say everything was finished by the seventh day. How do you be believe the words about water but not the words about days?
All his commands to nature were indeed finished, and to him that's the same thing as their being accomplished. You keep forgetting that God isn't trapped in time as we are (time was merely one of his creations). He gives a command and sees it accomplished instantly, even when, to our reckoning (being creatures trapped in time), it take millions of years.
